1. Field of the Invention
The present invention pertains to electrical ceiling device mounting assemblies and method and more particularly to mounting assemblies for ceiling fans, light fixtures or the like that may require stable heavy duty mounting structures.
2. Related Prior Art
Ceiling mounting structures for electrical devices have been requiring additional strength in our modern society with the advent of ceiling fans in addition to large electrical fixtures. Large electrical fixtures have always required added support to withstand the static load placed on the support structure. However, large electrical fixtures previously were the domain of large buildings such as hotels, large office buildings etc., due to the cost of the fixture. In our affluent economy large lighting fixtures have become popular to the extent that many homes have large chandeliers. Even more common are ceiling fans. Each of these fixtures has its own complications. Extremely large lighting fixtures have an increased static load, which must be accounted for in providing proper hanging devices. Ceiling fans may have a large heavy motor associated with the fan along with extensive lighting, which may increase the static load to the point where its hanging structure may become a consideration. However, in addition to the static load presented by the fan, motor and lighting, the fan rotation provides a dynamic load that requires design consideration in supplying a hanging structure.
There have been many efforts in the prior art to provide adequate structure to permit hanging electrical devices with high static and dynamic loads. The following patents are representative of the efforts in the prior art.
U.S. Pat. No. 4,892,211, titled "Ceiling Boxes for Ceiling Fan Support", issued to Robert W. Jorgensen relates to a ceiling box for mounting and supporting a ceiling fan to a ceiling. The ceiling box includes a top wall portion with a side wall portion surrounding the periphery of the top wall portion. The box is open at the end opposite the top wall portion and the side wall portion has a pair of flanges extending normal thereto into the open end of the box. These flanges have holes therein for receiving fan supporting screws. In a first embodiment, a pair of threaded mounting screw holes are formed in the top wall portion and are each axially aligned with an unthreaded hole that extends through the respective flange. In a second embodiment, the holes in the flanges are also threaded for added support.
U.S. Pat. No. 5,183,233, titled "Universal Fixture Support", issued to Joseph LaPalomento, relates to a support for hanging an electrical fixture to a ceiling or wall and a method for suspending the fixture. The support comprises a panel which is intended to be affixed to the grid work of a house and a support affixed to the panel which holds the electrical fixture. A slot is provided on the rear of the panel to hold the panel flush against a flat surface and to allow electrical wiring to connect to the electrical device.
U.S. Pat. No. 5,234,119, titled "Plastic Box For Ceiling Fan Support", issued to Robert W. Jorgensen et al., relates to a plastic ceiling box adapted to support a ceiling fan and adapted to be mounted on a structural member, such as a ceiling joist. The ceiling box comprises a body member having a lower wall and a pair of side walls defining a recess for snugly receiving the ceiling joist. Box mounting holes for receiving box mounting fasteners are located at opposite sides and ends of the lower wall for attaching the ceiling box to the joist. Openings for receiving fan supporting fasteners are formed in the body member adjacent the box member aid in attaching the body member to the joist. This overall arrangement provides sufficient support and strength to resist dynamic loads od a ceiling fan even though the ceiling box is formed of plastic.
U.S. Pat. No. 5,522,577, titled "Ceiling Fan Support Arrangement", issued to Mark Roesch, relates to a mounting assembly for supporting a ceiling fan from a ceiling that includes a support beam located inwardly of the ceiling surface at a predetermined distance. An electrical box having a bottom wall is directly joined to and supported from the support beam. The box has side walls extending from the bottom wall through the ceiling substantially to the exposed ceiling surface and terminating in an open end. A rigid metal plate or disk member adapted for supporting and mounting a ceiling fan is positioned over the open end of the box. The disk member is of a size sufficient to have a peripheral portion extending radially beyond the side walls of the box and a plurality of mounting screws extend from the metal disk member through the interior of the box into connected engagement with the beam for supporting the disk member from the beam without reliance on the electrical box.
Although the foregoing methods and apparatus have all attempted to solve the problem of increased loads on electrical ceiling fixtures, none have provided a universal solution that can be used either in a new installation or an existing installation that may or may not have a junction box mounted in the side of a ceiling joist.